Electromagnetic starter supporting feed far-end electric leakage test

Abstract

The utility model discloses an electromagnetic starter supporting a feed far-end electric leakage test. The electromagnetic starter comprises a comprehensive protector, an AC voltage transformer, an AC current transformer, a load side insulation resistance detection unit and a vacuum contactor. The vacuum contactor and the electric leakage test resistor are interlocked, three-phase alternating current flows in from the upstream low-voltage feed unit and supplies power to the motor after passing through the vacuum contactor, the alternating current voltage transformer is used for collecting the voltage of the three-phase alternating current, and the alternating current transformer is used for collecting the current of the three-phase alternating current. The load side insulation resistance detection unit is used for detecting a load side insulation resistance value. According to the electromagnetic starter supporting the feed far-end electric leakage test, the far-end electric leakage test and the electrical safety protection function are integrated, a load can be driven, electric leakage locking, overvoltage, undervoltage and other circuit protection can be carried out, and the tail end electric leakage test of a low-voltage feed switch can be carried out under the breaking condition.

Description

Technical Field

[0001] The utility model belongs to the technical field of electromagnetic starters, and in particular relates to an electromagnetic starter supporting a power-feed remote leakage test. Background Art

[0002] Coal mines have narrow passageways and high temperatures and humidity, making them prone to electrical leakage. Leakage can cause electric shocks, short circuits between phase lines, and arcing, which can trigger methane explosions. Therefore, Article 457 of the "Coal Mine Safety Regulations" (revised in 2010) explicitly requires that low-voltage distribution lines in coal mines be equipped with leakage detection and protection devices to automatically disconnect the affected line in the event of a leakage. These low-voltage leakage detection devices must also be tested daily for their effectiveness.

[0003] Traditional leakage testing methods primarily rely on connecting to a resistance box. This method requires manual installation and removal of grounding resistors, as well as closing and opening the circuit breaker. This cumbersome process requires collaboration and is difficult to perform. Furthermore, the lack of clear isolation points poses safety risks. Therefore, integrating leakage detection functionality is necessary to improve the functional integrity of existing electrical safety protection systems.

[0004] In recent years, many patents for improvements to the functions of electromagnetic starters have revolved around structural design. For example, patent application number CN202322071514.3 proposes a dustproof housing for a vacuum electromagnetic starter for mining; patent application number CN202320233688.2 discloses a multi-voltage integrated explosion-proof variable frequency starting device for mining, which improves explosion-proof performance; patent application number CN202223268018.9 discloses a protective mechanism for a vacuum electromagnetic starter for mining; and patent application number CN202222979361.8 discloses a multi-circuit vacuum electromagnetic starter with a leakage lockout protection circuit, which can reduce the impact force of falling gravel and protect the starter body. The above patents improve the dust and explosion-proof performance of electromagnetic starters, but lack the functional design of remote terminal leakage testing.

[0005] In terms of leakage testing, the patent with application number CN202011467642.4 proposes a remote leakage testing device for underground power lines in mines, which solves the problem that temporary power outages during leakage testing require repeated power outage and power supply operations at the line terminal and power supply end to prevent faults occurring during the test from causing electric shock accidents to personnel; the patent with application number CN202022993509.4 discloses a remote leakage testing device for underground power lines in coal mines, which solves the problem in existing leakage testing methods that after power outage and connection to the test resistor, the test resistor forms a leakage lock and power cannot be supplied for testing. Although the above patents all propose methods for remote leakage testing, they lack effective feedback and circuit protection for problems such as leakage and overload.

[0006] In summary, the existing design concept of independent remote leakage test and electromagnetic starter has problems such as high cost and inconvenient maintenance. Utility Model Content

[0007] The utility model provides an electromagnetic starter that supports remote leakage testing of power supply to solve the above-mentioned technical problems, and specifically adopts the following technical solutions:

[0008] An electromagnetic starter supporting a remote-end leakage test for power feeding comprises: a comprehensive protector, an AC voltage transformer, an AC current transformer, a load-side insulation resistance detection unit, and a vacuum contactor; the AC voltage transformer output end, the AC current transformer output end, the load-side insulation resistance detection unit output end, and the vacuum contactor control end are all connected to the comprehensive protector; the vacuum contactor and the leakage test resistor are interlocked; three-phase AC power flows from an upstream low-voltage feeder unit and supplies power to a motor after passing through the vacuum contactor; the AC voltage transformer is used to collect the voltage of the three-phase AC power; the AC current transformer is used to collect the current of the three-phase AC power; and the load-side insulation resistance detection unit is used to detect the insulation resistance value on the load side.

[0009] Furthermore, the AC current transformer detects the current value of each phase in the three-phase AC circuit and transmits it to the integrated protector.

[0010] Furthermore, the voltage transformer input end is located on the power supply side of the electromagnetic starter and is connected to the three-phase alternating current, and the voltage transformer output end is connected to the integrated protector.

[0011] Furthermore, the three-phase alternating current and the three-phase wiring of the motor respectively pass through the AC current transformer.

[0012] Furthermore, the power supply side of the vacuum contactor is connected to a low-voltage feeding unit, and the load side of the vacuum contactor is connected to a motor.

[0013] Furthermore, when the monitoring host sends a remote leakage test signal, the integrated protector of the electromagnetic starter receives the command, locks the vacuum contactor from closing, and puts the remote leakage test resistor connected to the power supply side of the electromagnetic starter into operation. The upper power feed switch receives the leakage signal, sends a leakage protection action, and completes the remote leakage test function.

[0014] Furthermore, it also includes a zero-sequence current transformer connected to the electromagnetic starter, and the zero-sequence current transformer is connected to the three-phase AC circuit for detecting leakage current.

[0015] The benefit of the present invention is that the electromagnetic starter that supports the remote leakage test of the power feed is provided, which integrates the remote leakage test with the electrical safety protection function. It can not only drive the load to perform leakage lockout, overvoltage and undervoltage and other circuit protection, but also perform the end leakage test of the low-voltage feeder switch when it is disconnected. The installation of special leakage test equipment underground in coal mines requires the addition of explosion-proof devices, and the explosion-proof devices must be routinely inspected once a month. The electromagnetic starter that supports the remote leakage test of the power feed in this application integrates the leakage test into the electromagnetic starter. There is no need to add additional explosion-proof equipment during on-site implementation, which can effectively reduce the cost of the entire system layout and application.

[0016] The utility model also benefits from providing an electromagnetic starter that supports remote feeder leakage testing, eliminating the tedious steps of installing and removing grounding resistors. This allows for easy and rapid deployment, ensuring system operational safety while improving leakage testing efficiency. The application of this patent also reduces maintenance personnel's reliance on specialized technical expertise, enabling even non-professionals to effectively maintain and manage the equipment, thereby reducing operational and maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0018] Figure 1 It is the overall functional structure of the mine electrical safety protection system;

[0019] Figure 2 This is a flowchart of the overload protection process of an electromagnetic starter supporting a feeder remote leakage test proposed in an embodiment of the present utility model;

[0020] Figure 3 A flowchart of the short-circuit protection process of an electromagnetic starter supporting a feeder remote leakage test proposed in an embodiment of the present utility model;

[0021] Figure 4 A flowchart of the phase failure protection of an electromagnetic starter supporting a feeder remote leakage test proposed in an embodiment of the present utility model;

[0022] Figure 5 A flowchart of the leakage lockout process of an electromagnetic starter supporting a feeder remote leakage test proposed in an embodiment of the utility model;

[0023] Figure 6 A flowchart of the undervoltage protection and overvoltage protection of an electromagnetic starter supporting a feeder remote leakage test proposed in an embodiment of the present utility model;

[0024] Figure 7 This is a circuit diagram of an electromagnetic starter embodiment supporting a power-feed remote leakage test proposed in an embodiment of the present utility model;

[0025] Figure 8 for Figure 7 An enlarged diagram of the circuit principle of the corresponding part of an electromagnetic starter that supports a feed-in remote leakage test;

[0026] Figure 9 for Figure 7 An enlarged diagram of the circuit principle of the corresponding part of an electromagnetic starter that supports a feed-in remote leakage test;

[0027] Figure 10 for Figure 7 An enlarged diagram of the circuit principle of the corresponding part of an electromagnetic starter that supports a feed-in remote leakage test;

[0028] Figure 11 for Figure 7 An enlarged diagram of the circuit principle of the corresponding part of an electromagnetic starter that supports power-feed remote leakage test. DETAILED DESCRIPTION

[0029] The following describes in detail embodiments of the present application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0030] In the description of this application, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0031] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0032] The present application discloses an electromagnetic starter that supports a remote leakage test for power feeding, comprising: a comprehensive protector, an AC voltage transformer, an AC current transformer, a load-side insulation resistance detection unit, and a vacuum contactor; the output end of the AC voltage transformer, the output end of the AC current transformer, the output end of the load-side insulation resistance detection unit, and the control end of the vacuum contactor are all connected to the comprehensive protector, the vacuum contactor and the leakage test resistor are interlocked, three-phase AC power flows from the upstream low-voltage feeder unit, and supplies power to the motor after passing through the vacuum contactor, the AC voltage transformer is used to collect the voltage of the three-phase AC power, the AC current transformer is used to collect the current of the three-phase AC power, and the load-side insulation resistance detection unit is used to detect the insulation resistance value of the load side. Specifically, the AC current transformer collects the current of the three-phase AC power and transmits it to the comprehensive protector, which compares the value with the rated load of the motor stored internally. When the current is abnormally large, it is determined that the circuit is overloaded; the comprehensive protector controls the action of the vacuum contactor to disconnect the AC power and the motor. When the integrated protector determines that the AC current collected by the AC current transformer exceeds the short-circuit multiple of the motor's rated current, it immediately controls the vacuum contactor to disconnect the motor from the AC power, thereby protecting the motor.

[0033] When the vacuum contactor is open, the load side insulation resistance detection unit detects the insulation resistance of the load side circuit. If the insulation resistance of the load side circuit drops to or below the set value, the integrated protector detects a fault and locks the vacuum contactor, preventing it from closing and supplying power, thus achieving leakage lockout. The working process of leakage lockout is as follows: Figure 1 Shown, including:

[0034] (1) Insulation resistance detection: The load-side insulation resistance detection unit detects the insulation resistance of the load-side circuit. When the resistance in the load circuit drops to or below the preset setting value, it is detected that the circuit insulation resistance is too low and a signal is sent to the integrated protector.

[0035] (2) Locking switch: The integrated protector issues a leakage locking command, locking the vacuum contactor to stop power supply, achieving leakage locking, thereby protecting the line and equipment from damage.

[0036] (3) Unlocking: When the resistance in the load circuit is restored, that is, the insulation resistance of the load side circuit is greater than the lock setting value, the integrated protector detects the resistance value recovery and unlocks the vacuum contactor, allowing it to reclose and power on to reset.

[0037] Remote leakage test

[0038] The electromagnetic starter communicates with the monitoring host, receives the leakage detection instruction, and performs the leakage test. The specific process is as follows:

[0039] (1) After receiving the leakage test instruction, the integrated protector checks the status of the vacuum contactor: if the vacuum contactor is in the closed state, it means that the circuit is connected and the load is safe. In this state, the equipment is operating normally; if the vacuum contactor is in the open state, the integrated protector selects the corresponding leakage test resistor according to the current system voltage level and starts the leakage test.

[0040] (2) The integrated protector monitors the circuit and detects three signals through the voltage transformer and zero-sequence current transformer connected to the integrated protector: whether there is a voltage loss, whether there is a zero-sequence current, and whether there is a leakage test signal. If these signals are detected, the leakage test is considered successful; otherwise, the leakage test is considered a failure.

[0041] (3) Record the action time of the low-voltage feeder. The action time refers to the time interval from the start of the leakage test to the successful leakage detection. Compare this time with the time specified in the GB / T 6829-2017 standard to ensure that the action time of the leakage protection device meets the national standard requirements.

[0042] (4) The integrated protector reports leakage test data, and the monitoring host evaluates the severity of the leakage based on it. It determines the hazard level of the leakage according to the set threshold, and provides a basis for subsequent disposal such as adjustment of the leakage detection frequency.

[0043] In the embodiment of the present application, an AC current transformer detects the current value of each phase in a three-phase AC circuit and transmits it to a comprehensive protector for analysis and judgment to implement overload and short-circuit protection functions.

[0044] In the implementation of the present application, the input end of the voltage transformer is located on the power supply side of the electromagnetic starter and is connected to the three-phase alternating current. The output end of the voltage transformer is connected to the integrated protector for analysis and judgment to realize undervoltage, overvoltage and phase failure protection functions.

[0045] In an embodiment of the present application, the three-phase alternating current and the three-phase wiring of the motor respectively pass through the AC current transformer.

[0046] In an embodiment of the present application, the power supply side of the vacuum contactor is connected to the low-voltage feeder unit, the load side of the vacuum contactor is connected to the motor, and the vacuum contactor feeds back the power supply status of the motor circuit to the integrated protector.

[0047] In an embodiment of the present application, when the monitoring host 101 sends a remote leakage test signal, the integrated protector of the electromagnetic starter 104 receives the command, locks the vacuum contactor from closing, and puts the remote leakage test resistor connected to the power supply side of the electromagnetic starter 104 into operation. The upper-level feeder switch receives the leakage signal, sends a leakage protection action, and completes the remote leakage test function.

[0048] In the embodiment of the present application, a zero-sequence current transformer is further included, which is connected to the electromagnetic starter 104 and is connected to the three-phase AC circuit to detect leakage current. The zero-sequence current transformer detects the presence of zero-sequence current as a basis for determining whether the leakage detection is successful.

[0049] The electromagnetic starter 104 is a motor control device widely used in electrical equipment. It forms an electrical safety protection system for coal mines together with the monitoring host 101, the ring network switch 102, the control master station 103, the low-voltage feeder switch and other equipment. Figure 1 Shown is the connection relationship between the relevant equipment. Figure 1 In the system, electromagnetic starter 104 consists of a comprehensive protector, an AC voltage transformer, an AC current transformer, a load-side insulation resistance detection unit, and a vacuum contactor. It features leakage protection, including locking and inputting leakage test resistors. It also exchanges information with the ring network switch 102 via an RS485 interface and fiber optic interface, transmitting this information to the monitoring host 101 in the ground control room. When a remote leakage test is required, the monitoring host 101 issues a leakage test command to the electromagnetic starter 104. The three-phase AC power controlled by the electromagnetic starter 104 is fed upstream through a low-voltage feeder switch. If leakage occurs in the circuit, the low-voltage feeder switch automatically cuts off the power supply, protecting the circuit.

[0050] The electromagnetic starter 104 can protect the motor and power supply line from overload, short circuit, leakage, undervoltage, and overvoltage faults, and has the function of inputting a remote leakage test resistor. The details are as follows:

[0051] Overload protection

[0052] Overload protection adopts the inverse time action principle, and the action time of the protection device is inversely proportional to the overload current. The specific working process of overload protection is as follows Figure 2 As shown, its protection characteristics are implemented with reference to Table 1.

[0053] Specific implementation plan:

[0054] (1) Current detection: The current transformer collects current data in real time. The integrated protector detects the current signal and compares it with the rated load of the motor. When the current is greater than the overload current setting value, the circuit is judged to be overloaded.

[0055] (2) Inverse time characteristic calculation: The integrated protector uses a built-in timer or related logic to delay the action according to the pre-set inverse time characteristic based on the detected current value. This inverse time characteristic is set according to industry standards when the electromagnetic starter leaves the factory.

[0056] (3) Timer timing: Once the integrated protector detects an overload, its internal timer starts timing.

[0057] (4) Disconnect the circuit: After the timing is completed, the integrated protector will again determine whether it is overloaded. If so, the vacuum contactor will interrupt the circuit to prevent further overload, thereby protecting the line and equipment from damage.

[0058] (5) Reset: When necessary, the vacuum contactor is manually or automatically reset after performing a circuit-breaking operation so that it can be put back into use after the fault is eliminated.

[0059] Table 1 Inverse time overload delay action characteristics

[0060]

[0061] Short-circuit protection

[0062] The short circuit multiple can be adjusted between 2-11 times of the rated current, and the short circuit action time is 200-400ms. Figure 3 As shown, when the current transformer detects that the real-time current exceeds the short-circuit multiple of the rated current, it will immediately disconnect the circuit. The initial state is cold, and the reset method can be power-off reset or manual reset.

[0063] Phase failure protection

[0064] The specific working process of phase failure protection is as follows: Figure 4 As shown, when the voltage and current transformers detect a failure (abnormal voltage) or overload (abnormal current) in one or more of the three phases of the circuit, phase failure protection is activated. Phase failure protection uses a definite time action principle. Refer to Table 2 for its protection characteristics.

[0065] Table 2 Definite time phase failure delay action characteristics

[0066]

[0067] Leakage lockout

[0068] When the low-voltage feeder is disconnected, the insulation resistance of the load-side circuit drops to or below the set value, indicating that leakage has occurred. The integrated protector detects the fault and prevents the vacuum contactor from closing and supplying power, thus achieving leakage lockout of the main circuit. The specific working process of leakage lockout is as follows: Figure 5 shown.

[0069] The specific implementation plan is as follows:

[0070] (1) Insulation resistance detection: When the resistance in the load circuit drops to or below the preset setting value in Table 3, the integrated protector detects that the circuit insulation resistance is too low and issues a blocking signal.

[0071] Table 3 Earth leakage blocking action value

[0072]

[0073] (2) Locking switch: The locking switch locks the vacuum contactor and prevents power from being supplied, thus achieving leakage locking and protecting the lines and equipment from damage.

[0074] (3) Unlocking: When the resistance in the load circuit is restored, that is, the insulation resistance of the load side circuit is greater than the locking resistance setting value, the integrated protector detects the resistance value recovery through the load side insulation resistance detection unit, unlocks the vacuum contactor, and allows it to reclose and power on to reset.

[0075] Undervoltage protection and overvoltage protection

[0076] Here, the grid voltage is sampled in real time and compared with its set value, and then it is judged whether it is undervoltage or overvoltage. The specific working process of undervoltage protection and overvoltage protection is as follows Figure 6 Shown, including:

[0077] (1) Voltage measurement and comparison: The integrated protector detects the voltage of the load circuit in real time through a voltage transformer and compares the measured voltage with two preset voltage setting values: one is the overvoltage threshold and the other is the undervoltage threshold. These thresholds are set by the user according to specific requirements and are usually 0.6-1 times the rated value to ensure that the circuit operates within an ideal voltage range. If the measured voltage is lower than the undervoltage threshold, the undervoltage protection mechanism is triggered. Similarly, if the measured voltage is higher than the overvoltage threshold, the overvoltage protection mechanism is triggered.

[0078] (3) Delay judgment: To avoid frequent switching actions due to voltage fluctuations, a delay of 1 to 30 seconds is usually set before triggering the protection action. The timing starts after receiving the overvoltage or undervoltage signal. If the voltage returns to the normal range during the delay period, the protection action is canceled; otherwise, the protection action is executed.

[0079] (4) Protection action: The integrated protector sends a circuit breaker command to the vacuum contactor to disconnect the power supply.

[0080] (5) Reset: When the voltage in the load circuit returns to within the preset setting value, the integrated protector controls the vacuum contactor to close and power on again for reset.

[0081] Remote leakage test

[0082] The electromagnetic starter communicates with the monitoring host, receives the leakage detection instruction, and performs the leakage test. The specific process is as follows:

[0083] (1) After receiving the leakage test instruction from the upstream monitoring host, the integrated protector checks the status of the vacuum contactor: if the vacuum contactor is in the closed state, it means that the circuit is connected and the load is safe. In this state, the integrated protector will notify the monitoring host that the equipment is operating normally and remote leakage test is not allowed; if the vacuum contactor is in the open state, the system will input the corresponding leakage test resistor according to the current voltage level and start the leakage test.

[0084] (2) The integrated protector monitors the circuit, focusing on three main signals: whether there is a voltage loss, whether there is a zero-sequence current, and whether there is a leakage lockout signal. If these signals are detected, the leakage detection is considered successful; otherwise, the leakage detection is considered a failure.

[0085] (3) The integrated protector records the operating time of the upstream low-voltage feeder switch. The operating time refers to the time interval from the start of the leakage test to the successful leakage detection. This time is compared with the time specified in the GB / T 6829-2017 standard to ensure that the operating time of the leakage protection device meets the national standard requirements.

[0086] (4) The integrated protector records leakage data and reports it to the monitoring host, based on which the severity of the leakage is assessed and the hazard level of the leakage is determined according to the set threshold, providing a basis for subsequent disposal such as adjustment of the leakage monitoring frequency.

[0087] Leakage test frequency

[0088] Although the "Detailed Rules for the Installation, Operation, Maintenance and Inspection of Low-voltage Leakage Detection and Protection Devices in Underground Coal Mines" stipulates that leakage tests should be conducted at least once a month, in actual operation, if there is a greater risk of leakage in the circuit system, the corresponding leakage tests should be conducted more frequently to detect leakage problems more promptly.

[0089] The monitoring host dynamically adjusts the number and frequency of remote leakage tests based on the number of faults (e.g., overload, short circuit, leakage, undervoltage, overvoltage) that occur within a fixed period of time during equipment operation. For example, an increase in faults over a period of time indicates a significant equipment risk, necessitating an increased test frequency to closely monitor the equipment's operating status. Conversely, if the number of faults decreases, the test frequency can be appropriately reduced to reduce the equipment's operating load. Specific leakage self-test cycles are shown in Table 4.

[0090] Table 4 Leakage self-test cycle table

[0091]

[0092] like Figure 7-11 Shown is the circuit principle of a specific embodiment of the electromagnetic starter supporting the power feeding remote leakage test of the present application.

[0093] (1) The three-phase AC power X1, X2, and X3 input from the upstream low-voltage feeder is connected to the AC motor terminals W, U, and V through the vacuum contactor KM1. The phase voltages of X1 and X3 are connected to the 36 and 37 pins of the integrated protector after passing through the voltage transformer BK1, and are used as the system voltage to power the integrated protector.

[0094] (2) The AC current values ​​measured by current transformers DH1, DH2, and DH3 are input to pins 26, 27, and 28 of the integrated protector, respectively. The integrated protector collects current data in real time and compares it with the rated load of the motor to determine whether it is overloaded. If the AC current value is abnormally large, it is determined whether a short circuit has occurred. If the zero-sequence current transformer DH4 detects a certain amount of leakage current, it is determined to be a leakage current.

[0095] (3) Detect the system voltage at pins 36 and 37. Based on the transformation ratio of the voltage transformer BK1, the phase voltage between X1 and X3 can be calculated as the basis for judging undervoltage and overvoltage faults.

[0096] (4) Remote leakage test:

[0097] ① The remote control box of the electromagnetic starter is connected to pins 33 and 34 of the integrated protector. Press the start button to connect pins 33-34. Press the stop button to disconnect pins 33-34.

[0098] ② Connect relay 1 between pins 38 and 39. When pins 38 and 39 are disconnected, the coil of intermediate relay ZJ1 loses power, and the normally open point ZJ1-1 opens. Consequently, the coil of vacuum contactor KM1 loses power, and KM1 opens. Conversely, pins 38 and 39 connect, and KM1 closes. This interlocks vacuum contactor KM1 with leakage tester J1.

[0099] ③ To begin the leakage test, power on J1, disconnect J1-1, close J1-2, and close J1-3. Detecting the zero-sequence current transformer confirms the start of the circuit leakage test based on the presence or absence of leakage current. Detecting the system voltage between pins 36 and 37 determines whether the upstream low-voltage feeder switch is operating.

[0100] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form, and any technical solution obtained by equivalent replacement or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. An electromagnetic starter supporting a power-feed remote leakage test, characterized in that: include: A comprehensive protector, an AC voltage transformer, an AC current transformer, a load-side insulation resistance detection unit and a vacuum contactor; the AC voltage transformer output end, the AC current transformer output end, the load-side insulation resistance detection unit output end and the vacuum contactor control end are all connected to the comprehensive protector, the vacuum contactor and the leakage test resistor are interlocked, three-phase AC power flows in from the upstream low-voltage feeding unit, and supplies power to the motor after passing through the vacuum contactor. The AC voltage transformer is used to collect the voltage of the three-phase AC power, the AC current transformer is used to collect the current of the three-phase AC power, and the load-side insulation resistance detection unit is used to detect the insulation resistance value on the load side.

2. The electromagnetic starter supporting the remote leakage test of power feeding according to claim 1, characterized in that: The AC current transformer detects the current value of each phase in the three-phase AC circuit and transmits it to the integrated protector.

3. The electromagnetic starter supporting the remote leakage test of power feeding according to claim 1, characterized in that: The voltage transformer input end is located on the power supply side of the electromagnetic starter and is connected to the three-phase alternating current, and the voltage transformer output end is connected to the integrated protector.

4. The electromagnetic starter supporting a power-feed remote leakage test according to claim 1, characterized in that: The three-phase alternating current and the three-phase wiring of the motor both pass through the AC current transformer respectively.

5. The electromagnetic starter supporting the remote leakage test of power feeding according to claim 1, characterized in that: The power supply side of the vacuum contactor is connected to a low-voltage feed unit, and the load side of the vacuum contactor is connected to a motor.

6. The electromagnetic starter supporting the remote leakage test of power feeding according to any one of claims 1 to 5, characterized in that: It also includes a zero-sequence current transformer connected to the electromagnetic starter, and the zero-sequence current transformer is connected to the three-phase alternating current circuit for detecting leakage current.

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